BAEL-7346: Parse Java Source Code and Extract Methods (#15409)

core-java-modules/core-java-sun/src/test/java/com/baeldung/extractjava/ExtractJavaLiveTest.java

@@ -0,0 +1,94 @@
+package com.baeldung.extractjava;
+
+import com.sun.source.tree.ClassTree;
+import com.sun.source.tree.CompilationUnitTree;
+import com.sun.source.tree.MethodTree;
+import com.sun.source.tree.Tree;
+import com.sun.source.util.JavacTask;
+import com.sun.source.util.SimpleTreeVisitor;
+import org.junit.Test;
+
+import javax.tools.JavaCompiler;
+import javax.tools.JavaFileObject;
+import javax.tools.StandardJavaFileManager;
+import javax.tools.ToolProvider;
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+
+public class ExtractJavaLiveTest {
+    @Test
+    public void visitTypeDeclsForClasses() throws Exception {
+        CompilationUnitTree compilationUnitTree = parseFile();
+
+        for (Tree tree : compilationUnitTree.getTypeDecls()) {
+            tree.accept(new SimpleTreeVisitor() {
+                @Override
+                public Object visitClass(ClassTree classTree, Object o) {
+                    System.out.println("Found class: " + classTree.getSimpleName());
+                    return null;
+                }
+            }, null);
+        }
+    }
+
+    @Test
+    public void iterateTypeDeclsForClasses() throws Exception {
+        CompilationUnitTree compilationUnitTree = parseFile();
+
+        for (Tree tree : compilationUnitTree.getTypeDecls()) {
+            if (tree.getKind() == Tree.Kind.CLASS) {
+                ClassTree classTree = (ClassTree) tree;
+                System.out.println("Found class: " + classTree.getSimpleName());
+            }
+        }
+    }
+
+    @Test
+    public void visitMethodsForClass() throws Exception {
+        CompilationUnitTree compilationUnitTree = parseFile();
+
+        for (Tree tree : compilationUnitTree.getTypeDecls()) {
+            if (tree.getKind() == Tree.Kind.CLASS) {
+                ClassTree classTree = (ClassTree) tree;
+                visitClassMethods(classTree);
+            }
+        }
+
+    }
+
+    private void visitClassMethods(ClassTree classTree) {
+        for (Tree member : classTree.getMembers()) {
+            member.accept(new SimpleTreeVisitor(){
+                @Override
+                public Object visitMethod(MethodTree methodTree, Object o) {
+                    System.out.println("Found method: " + classTree.getSimpleName() + "." + methodTree.getName());
+                    System.out.println("Return value: " + methodTree.getReturnType());
+                    System.out.println("Parameters: " + methodTree.getParameters());
+
+                    for (Tree statement : methodTree.getBody().getStatements()) {
+                        System.out.println("Found statement: " + statement);
+                    }
+
+                    return null;
+                }
+            }, null);
+        }
+    }
+
+    private static CompilationUnitTree parseFile() throws IOException {
+        String filename = "src/test/java/com/baeldung/extractjava/ExtractJavaUnitTest.java";
+
+        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+
+        StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, StandardCharsets.UTF_8);
+        Iterable<? extends JavaFileObject> compilationUnits = fileManager.getJavaFileObjectsFromFiles(Arrays.asList(new File(filename)));
+
+        JavacTask javacTask = (JavacTask) compiler.getTask(null, fileManager, null, null, null, compilationUnits);
+        Iterable<? extends CompilationUnitTree> compilationUnitTrees = javacTask.parse();
+
+        CompilationUnitTree compilationUnitTree = compilationUnitTrees.iterator().next();
+        return compilationUnitTree;
+    }
+}